OK, put the sail switch on the outlet side and have it drop out the relay on a no flow, or low flow condition.
Pump never over heats. Reset the relay to regain flow after clearing the inlet.
I used to build custom "Heat transfer packages" for large buildings.
Lynn E. Hanover
In a message dated 8/13/2019 2:48:03 AM Eastern Standard Time, flyrotary@lancaironline.net writes: